#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <unistd.h>
#include<stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
void writer(int wfd)
{
    const char *str="hello father! I am child";
    char buffer[1024];
    int cnt=0;
    pid_t pid=getpid();
    while(1)
    {
        snprintf(buffer,sizeof(buffer),"message:%s,pid:%d,cnt:%d\n",str,pid,cnt);

        write(wfd,buffer,strlen(buffer));
        cnt++;
        sleep(1);
    }
}
void reader(int rfd)
{
    char buffer[1024];
    while(1)
    {
        size_t n=read(rfd,buffer,sizeof(buffer)-1);
        (void)n;
        printf("I am father,I get message:%s\n",buffer);
    }
}
int main()
{
    // 1.创建管道
    int pipefd[2];
    int n = pipe(pipefd);
    if (n < 0)
        return 1;

    printf("pipefd[0]: %d,pipefd[1]: %d\n", pipefd[0], pipefd[1]);
    // 0:读端 1:写端
    // 2.子进程进行写入，父进程进行读取
    pid_t id = fork();
    if (id == 0)
    {
        // child:w
        close(pipefd[0]);
        writer(pipefd[1]);
        exit(0);
    }
    // father:r
    close(pipefd[1]);
    reader(pipefd[0]);

    wait(NULL);
    return 0;
}